1. Field of the Invention
This invention relates generally to fluid dispensing apparatus and more particularly to apparatus for delivering fluid to a utilization device and a closed loop system for cleaning the apparatus and the utilization device.
2. Description of the Prior Art
One example of the prior art that is generally related to the present invention is disclosed in U.S. Pat. No. 3,278,975 granted on Oct. 18, 1966. Therein there is disclosed a portable, automatic paint brush that includes a handle having bristles thereon. A paint inlet passage and a paint outlet passage entend axially through the handle and an adjustable valve is positioned in the handle for interconnecting the inner ends of the paint inlet and outlet passages in order to regulate the quantity of paint that circulates through the inlet and outlet passages. The adjustable valve includes a valve chest that is located between the ends of the inlet and outlet passages. Means defining a passage that is operably related to the valve chest and the brush assembly is used for supplying a portion of the circulating fluid, for example, paint, to the brush assembly. A stop valve is operably related to the passage between the valve chest and the brush assembly. A paint pump and a paint tank are connected to the paint inlet and outlet passages.
While the prior art just described is effective, it does exhibit several drawbacks as compared to the present invention. For example, the prior art does not provide means for permitting the pump to run continuously without delivering paint to the brush. Nor does the prior art provide means for delivering a major portion of the paint flow to the brush with a minor portion of the paint flow being simultaneously returned to the source of supply. Perhaps the most readily apparent shortcoming of the prior art is the complete absence of any means for cleaning the system.